Area Forecast Discussion
Issued by NWS Phoenix, AZ
Issued by NWS Phoenix, AZ
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039 FXUS65 KPSR 292322 AFDPSR Area Forecast Discussion National Weather Service Phoenix AZ 420 PM MST Wed May 29 2024 .UPDATE... Updated Aviation && .SYNOPSIS... Dry and tranquil weather conditions will persist through at least the weekend, but expect continued above normal temperatures as high pressure generally dominates across the region. High temperatures each day across the lower deserts will remain several degrees above normal with readings between 100 and 106 degrees under sunny to mostly sunny skies. && .DISCUSSION... The hot, dry, and tranquil weather pattern persists across the Southwest as dry zonal flow prevails with upper ridging now shifting east across the central CONUS. This pattern will continue to promote abundant sunshine across the region with current visible satellite imagery this afternoon only showing a few passing high clouds across the state. Ensemble guidance indicate 500 mb heights will remain steady around 583-585 dm through the remainder of this week and into the start of next week. This will keep afternoon temperatures each day several degrees above normal as lower desert highs top out in the 100-106 degree range for most places. With these temperatures will come widespread Minor and pockets of Moderate HeatRisk, so the necessary heat safety precautions should be exercised. Given the current pattern, winds each day will overall remain light outside of periodic afternoon wind gusts to around 20 mph. A weak shortwave pushing through the Southwest this weekend may slightly enhance winds and also lead to a degree or two dip in temperatures. Going into the middle part of next week, uncertainty increases as ensemble and deterministic models depict a cutoff low setting up off the coast of southern California and the Baja Peninsula while strong ridging builds across the western CONUS. Ensemble cluster analysis shows good agreement in regards to ridging building/strengthening over the western CONUS, but the strength and position of the cutoff low is uncertain. At this point, little in the way of sensible impacts is expected from the cutoff low with the greater impacts coming from the aforementioned ridge. Global ensembles indicate the ridge pushing average 500 mb heights to around 590 dm, which would translate to temperatures climbing well above normal. NBM temperature forecast spread increases mid/late next given some of the aforementioned uncertainty, but overall temperature trends increase closer to 110 degrees. The average (1991-2020) first occurrence of 110 degrees in Phoenix and Yuma is June 11th and for El Centro is June 14th, so the first occurrence would be slightly earlier than normal if temperatures were to reach 110 degrees in these places next week. && .AVIATION...Updated at 2320Z. South-Central Arizona including KPHX, KIWA, KSDL, KDVT; and Southeast California/Southwest Arizona including KIPL and KBLH: No major weather issues will exist through Thursday evening under clear skies. Wind trends around the Phoenix metro will be nearly identical to the past 24 hours favoring west winds through the afternoon and evening with a few occasional gusts around 15kt. Across SE California, a westerly component will be primarily preferred at KIPL, while south winds should be more common at KBLH. Periods of light and variable winds will be typical across the region at times. && .FIRE WEATHER... Hot and dry conditions will prevail through the remainder of this week with daily highs remaining above normal. Overall light winds will follow diurnal tendencies each day with afternoon gusts in the mid-teens to around 20 mph. MinRH values will range between 5-10% each afternoon while overnight Max RHs range between 20-40% for most places. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ DISCUSSION...Smith AVIATION...18 FIRE WEATHER...Smith/Kuhlman